What type of oil pump is primarily driven from the front of the crankshaft?

The external gear pump is primarily driven from the front of the crankshaft due to its design and placement within the engine. This type of pump utilizes two interlocking gears that create a flow of oil as they rotate. By being directly mounted at the front of the crankshaft, it allows for efficient oil circulation, which is crucial for lubrication and engine cooling during operation.

The external gear pump is commonly used in modern engines because it offers a high flow rate and consistent oil supply, essential for maintaining proper engine function. This setup not only optimizes space within the engine bay but also provides easy access for maintenance and replacement if necessary.

Other types of pumps, while they might be used in oil circulation systems, are not necessarily driven by the crankshaft or may have different mounting configurations that do not position them at the front. Therefore, the external gear pump stands out in this context for its specific characteristics and operational efficiency.